The present invention relates to a multilayer sheet material that is capable of being adhered to a foamed polymer core material, to shaped articles made from said multilayer sheet material, and to a process for making said multilayer sheet material.
The present invention arose out of a need to create body boards, or wave boards, surf boards, or skim boards, having intricate designs printed thereon. A body board is a shaped article used primarily for riding on waves. In addition, a body board can be used to skim across or float on water. Body boards generally are made from a polyethylene foam core. One side of the body board may have a cushiony layer for contact against the body. In addition, many body boards have laminated onto the other side of the foam core a layer of high density polyethylene (HDPE). This other side of the board is the side in contact with the water. The HDPE is used to prevent gouging on the surface of the body board. Gouging can be caused, for example, from impact of the body board with sand or shells on the bottom of the ocean.
There currently exists a desire in the marketplace to create body boards having detailed designs printed on them. HDPE, it was found, could be solidly colored or silk screen printed. However, it was not possible to print detailed designs on HDPE via silk screen printing.
Technology has been developed that permits detailed designs to be printed onto certain polymeric sheet materials, such as, for example, polybutylene terephthalate (PBT) sheet. This technology is referred to as sublimination printing and is described in U.S. Pat. No. 4,587,155, incorporated herein by reference. However, it was found to be very difficult to adhere this printable sheet material to a foamed polymer core material because of dissimilar polymeric chemistries between the printable sheet material and the foamed polymer core material. In the present invention, there was discovered a process for making a multilayer sheet material, using this printable sheet material, that could be adhered to a foamed polymer core material. As a result, body boards having detailed designs, which serve to enhance the shelf appeal of the boards, printed thereon could now be produced. In addition, the multilayer sheet material of the present invention, when adhered to a foamed polymer core material, can be shaped into other articles, such as, for example, floating docks, buoys, crash barriers, and rafts. It was further found that a body board made using the multilayer sheet material of the present invention was stiffer than a comparable body board made using conventional HDPE as an outer layer. As such, even if the printable sheet material used in the multilayer sheet material of the present invention does not have a design printed on it, articles made from such a material can be more beneficial than articles made from HDPE in cases where increased stiffness in the resultant article is desired.